首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14529篇
  免费   663篇
  国内免费   118篇
耳鼻咽喉   184篇
儿科学   293篇
妇产科学   153篇
基础医学   1637篇
口腔科学   398篇
临床医学   1046篇
内科学   4039篇
皮肤病学   199篇
神经病学   1294篇
特种医学   414篇
外科学   2536篇
综合类   87篇
一般理论   1篇
预防医学   445篇
眼科学   314篇
药学   958篇
中国医学   37篇
肿瘤学   1275篇
  2023年   106篇
  2022年   173篇
  2021年   337篇
  2020年   169篇
  2019年   223篇
  2018年   320篇
  2017年   253篇
  2016年   286篇
  2015年   312篇
  2014年   361篇
  2013年   424篇
  2012年   700篇
  2011年   841篇
  2010年   501篇
  2009年   386篇
  2008年   665篇
  2007年   752篇
  2006年   743篇
  2005年   677篇
  2004年   716篇
  2003年   678篇
  2002年   705篇
  2001年   417篇
  2000年   365篇
  1999年   377篇
  1998年   172篇
  1997年   156篇
  1996年   143篇
  1995年   110篇
  1994年   108篇
  1993年   105篇
  1992年   296篇
  1991年   229篇
  1990年   202篇
  1989年   232篇
  1988年   199篇
  1987年   232篇
  1986年   192篇
  1985年   187篇
  1984年   132篇
  1983年   113篇
  1979年   121篇
  1978年   59篇
  1975年   56篇
  1974年   68篇
  1973年   55篇
  1972年   56篇
  1970年   73篇
  1968年   64篇
  1967年   62篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
We compared midazolam 0.2 mg.kg-1 and fentanyl 50 micrograms with thiamylal 4 mg.kg-1 for rapid sequence induction. We could use midazolam safely in patients with bronchial asthma or drug allergy. There was no difference in time from the beginning of induction to intubation between midazolam treated group and thiamylal treated group. Changes in systolic as well as diastolic blood pressure and heart rate during 2 hours from intubation were smaller in midazolam treated group than in thiamylal treated group. In midazolam treated group, no arrhythmias were observed at the time of intubation. We could reduce the amount of anesthetics in midazolam treated group during 2 hours from intubation. From the results mentioned above, we conclude that midazolam is a useful agent for rapid sequence induction.  相似文献   
13.
14.
15.
Recombinant human erythropoietin (rHuEPO) has been reported to induce hypertension. We investigated the effect of a single injection of rHuEPO on blood pressure in patients receiving hemodialysis (HD) and in patients with predialysis chronic renal failure (CRF). Forty-one patients receiving HD and 36 patients with predialysis CRF received an intravenous injection of rHuEPO, and blood pressure and plasma endothelin-1 were measured before and 30 min after the injection. Mean blood pressure was increased significantly in HD patients, but not in CRF patients (HD: 103+/-5 to 105+/-6 mmHg, p<0.05; CRF: 103+/-4 to 103+/-6, NS). The percentage of patients with increased mean blood pressure of more than 10 mmHg after rHuEPO injection was significantly larger in the HD than in the CRF group (27.0% vs. 5.5%, p<0.01). A positive correlation was found between changes in endothelin-1 level and mean blood pressure in the HD (r=0.43, p<0.01) but not in predialysis chronic renal failure. In conclusion, a single injection of rHuEPO increased blood pressure with a positive correlation with endothelin-1 release in hemodialysis patients, but not in predialysis chronic renal failure patients.  相似文献   
16.
Some chordomas have a very poor prognosis because of their aggressive growth nature, but the efficacy of repeat operations for these cases has not been well documented. This report concerns 3 patients with aggressive chordoma of the clivus, who underwent operations 6 to 12 times over a period of 8 to 17 years because of symptomatic regrowth. Overall mean interval between repeat operations was 18 months with a range from 5 to 57 months and survival times were 9 to19 years after the first surgery. Main symptoms before each operation were diplopia and visual disturbance. Repeat palliative operations by intentional extradural debulking of the tumour to decompress offending neural structures, as well as maximal removal of the tumour, using appropriate skull base approaches, can mitigate progressive symptoms, and may result in better quality and some prolongation of life, although our patients gradually deteriorated neurologically throughout the clinical course.  相似文献   
17.
Endocrine tumor of the pancreas is potentially malignant. A multicenter analysis of these tumors was conducted to clarity the present status of their surgical management and the subsequent long-term surgical results. The Japan pancreatoduodenectomy (JPD) study group carried out the study; 368 patients were enrolled and variables related to tumor characteristics, surgery, and survival were retrospectively analyzed. There were 222 patients with functioning tumor and 143 patients with nonfunctioning tumor. Malignant tumor was found in 140 of 368 (38%) of the patients, and 63/140 (45%) of these patients had metastatic lesion; the most common site of the metastasis was liver 34/136 (25%), followed by regional lymph nodes 26/136 (19%). Pancreatic resection was performed in 91% of patients with nonfunctional tumor and in 83% of those with malignant tumor, and 73% of the pancreatic resections were done with lymph node dissection. The overall 5-year actuarial survival rate was 76% in patients with malignant tumor. The actuarial 5-year survival rate was 93% in the patients without metastasis and 83% in patients who received curative resection. Multivariate analysis showed that the presence or absence of synchronous metastasis was the sole significant prognostic factor. The results suggest that: (i) malignant endocrine tumor of the pancreas is a curable malignancy when pancreatic resection with lymph node dissection is adopted and (ii) that synchronous metastasis is the dominant prognostic factor. This study was carried out as a group project. The authors' institutions are as follows  相似文献   
18.
19.
20.
The pro-drugs of alpha,2-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine-7-acetic acid(I) with a potent anti-inflammatory activity were synthesized in order to reduce its gastrointestinal side effects. Various esters synthesized were evaluated for their anti-inflammatory activity and ulcerogenicity. Among the compounds maintaining a potent activity of I, N,N-dimethylcarbamoylmethyl alpha,2-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine-7-acetate (II-18) showed excellent biopharmaceutical characteristics. The ulcerogenic effect of II-18 on the rat gastric mucosa was about 3 times less than that of I. It was suggested that II-18 may be an useful biolabile pro-drug for I among the compounds tested.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号